I'm using LPC11A14. The pull-up fail when I configure the main source clock

henryfabriciopi — Wed, 13 Jul 2016 02:59:08 GMT

In the LPC11A14, I need to use the on chip pull-up resistor on my GPIO P0_28 as input port. It works good. But it fail when I configure de PLL output as my main clock source.

MAINCLKUEN_bit.ENA = 0; // in this point the pull-up is working very good!

MAINCLKSEL_bit.SEL = 3; // in this point the pull-up is working very good!

MAINCLKUEN_bit.ENA = 1; // after execution of this code, the pull-up is no more working.

To see the pull-up active, I used a voltmeter in the P0_28 pin. When it is working, I see 2,8V (I expected 3,3V, but with 2,8V is working). But when it is not working, I see 0,6V in this pin.

I used the function InitClock to configure the main clock and the PLL. If I change the divisor (second parameter), the voltage in the pin changes too.

For more informations, my complete code is:

void main(void)

{

//GPIO configuration:

P0DIR_bit.DIR28=0;

IOCON_P0_28_bit.FUNC=0;

IOCON_P0_28_bit.MODE=2;

//Configuration of clock

InitClock(240MHZ, 5); //<<< PROBLEM INSIDE THIS FUNCTION

while(true) { /* my code */ }

}

void InitClock(Int32U pllclock, Int32U ahbdiv) //page. 27

{

/* Enable XTAL Oscilator */

PDRUNCFG_bit.XTAL_PD = 0;

/* Enable Internal RC oscilator */

PDRUNCFG_bit.IRC_PD = 0;

/* Select internal RC oscilator for SYS clock source */

MAINCLKUEN_bit.ENA = 0;

MAINCLKSEL_bit.SEL = 0;

MAINCLKUEN_bit.ENA = 1;

/* Configure System PLL */

/* Power-down System PLL */

PDRUNCFG_bit.SYSPLL_PD = 1;

/* Select XTAL Oscilator for SYS PLL input */

SYSPLLCLKUEN_bit.ENA = 0;

SYSPLLCLKSEL_bit.SEL = 0; //0=IRC, 1=XTAL, 2=CLKIN pin

SYSPLLCLKUEN_bit.ENA = 1;

/* Calculate M */

Int32U m = pllclock/(XTAL_OSC_FREQ*(2*2)) - 1;

assert(m<32);

/* Configure PLL frequency */

SYSPLLCTRL_bit.MSEL = m;

SYSPLLCTRL_bit.PSEL = 1;

/* Power-up PLL */

PDRUNCFG_bit.SYSPLL_PD = 0;

/* Set System AHB Clock divider */

SYSAHBCLKDIV_bit.DIV = ahbdiv;

/* Wait until PLL locks */

while(!(SYSPLLSTAT_bit.LOCK));

/* Select System PLL Output for SYS clock source */ //page. 20

MAINCLKUEN_bit.ENA = 0;

MAINCLKSEL_bit.SEL = 3;

MAINCLKUEN_bit.ENA = 1; //<<< PROBLEM AFTER THIS EXECUTION

}

Re: I'm using LPC11A14. The pull-up fail when I configure the main source clock

DavidS — Wed, 13 Jul 2016 21:35:43 GMT

Hi Henry,

Sorry I don't have a board to try and test.

One question. Did you enable the SYSAHBCLKCTRL[IOCON] block clock?

Regards,

David

Re: I'm using LPC11A14. The pull-up fail when I configure the main source clock

henryfabriciopi — Thu, 14 Jul 2016 00:04:13 GMT

Yes, I do it in my code:

/* Enable GPIO Clock */

SYSAHBCLKCTRL_bit.GPIO = 1;

/* Enable IOCON Clock */

SYSAHBCLKCTRL_bit.IOCON = 1;

Re: I'm using LPC11A14. The pull-up fail when I configure the main source clock

henryfabriciopi — Wed, 27 Jul 2016 12:51:12 GMT

I found the solution. I changed the microcontroler and now is working.

Thanks for all.

Henry

topic Re: I'm using LPC11A14. The pull-up fail when I configure the main source clock in LPC Microcontrollers

I'm using LPC11A14. The pull-up fail when I configure the main source clock

Re: I'm using LPC11A14. The pull-up fail when I configure the main source clock

Re: I'm using LPC11A14. The pull-up fail when I configure the main source clock

Re: I'm using LPC11A14. The pull-up fail when I configure the main source clock